The present invention relates to a floating barrier of the kind used on bodies of water to prevent and control pollution. It relates particularly to a floating barrier of the kind used for oil spills.
Research is showing that ecological damage continues long after all visible traces of spilled oil are gone. While the use of chemical dispersants speeded the elimination of oil from the water they contributed to the long-term degradation of environmental conditions in and on the bottom of the water. Although major catastrophes such as the wreck of the Ocean Eagle at Puerto Rico, the Torrey Canyon off the coast of England or the Santa Barbara Channel blowout in California have received the headlines, the smaller day-to-day oil spills in coastal waters and harbors of the world produce chronic pollution that is much larger in total volume and more severe in biological consequences.
As a result of these findings Federal and local laws have been passed dealing with these problems. These laws require that certain safety measures be adhered to during the transfer of oil where a spill might occur. Among other safeguards an oil spill containment barrier is required to be either in place or available for use in the event of an accidental oil spill.
Experience and research have shown that the floating oil containment barrier is the most effective piece of equipment used to limit the disastrous effects of spilled oil. A good barrier, properly used, keeps the oil from spreading out and becoming "lost" and prevents such lost oil from killing waterfowl, poisoning acquatic life and fouling property. The cost of recovery of oil that has been properly contained is sufficiently below the costs of extensive cleanup operations from a "lost" spill to justify many times over the price of a containment barrier.
The efficacy of an oil containment barrier is dependent on many factors. It must be efficient, rugged, simple, and reliable in operation. In most cases portability and speed of deployment are essential; and, ideally, the barrier would be easily cleaned and reusable after an oil spill. Also, since space is usually at a premium in maritime operations, any barrier used by the industry must be compact to stow. Furthermore, any barriers which embody the above qualities must be produced at a cost competitive with barriers presently in use.
A study of barriers presently in use fails to find one that meets all, or even most of the criteria mentioned above. For example; the common "sausage" type barrier (which consists of a long cylindrical float supporting a flexible fin ballasted to hang in the water for the length of the float) is inadequate to contain oil under any but mill pond conditions. It is also bulky and flimsy in construction, unless specifically manufactured to be effective and rugged, in which case it becomes huge and unwieldly and disproportionately expensive. Attempts to solve the problems of bulk in "sausage" type barriers have led to the development of "inflatables" which are compact to store and quick to deploy, but which are, of course, very much subject to the puncturing from the masses of trash usually found floating in ports and harbors. An oil spill brings out myriads of work boats, tugboats, barges and observer craft, any of which are liable to sink an inflatable barrier with propellers, boathooks, jagged steel edges, chafing barnacles, pinching, etc. In many cases the portability of an "inflatable" is limited by the portability of its air compressor.
Belt-type barriers (which characteristically have a long, rather flat flexible curtain designed to float upright in the water) are capable of solving the problems of deploying, storage, and ruggedness and in addition are usually easy to clean and can be produced at a practical cost. However, their upright design makes them inherently unstable in the water and subject to heeling over in waves or currents, with subsequent escape of oil. In the past, when problems of instability in an otherwise effective barrier were attempted to be solved by makers who offset the flotation with outriggers, compactness and/or deployability were sacrificed. The further out the stabilizing flotation extends the more space the barrier occupies both in storage and in use. Oil and debris are not free to move along the face of such a barrier, and the barrier tends to snag when towed and cannot be deployed in the confined places characteristic of busy and crowded ports.
It was therfore a primary object of the present invention to construct a barrier that meets the specifications listed above while avoiding the failings and shortcomings of the prior art.